These videos are teasers of an animated film about one of the best known folk creatures of the Amazon, the Mapinguari.

According to the mestizos have the Mapinguari, is a hairy giant with one eye in the forehead and mouth at the navel, and there are also those who say that your feet have the shape of a pestle, and a sound similar to the cries of hunters , which is a way of him finding prey (hunters).

The few hunters who survive the encounter with the Mapinguari often get maimed or terrible marks on the body for the rest of their lives. By speaking the creature walks through the forests of the day, keeping the night to sleep. During his walks through the forest he will screaming, breaking branches and felling trees, and some say that it only runs when you see a sloth.

By EDWIN McDOWELL; Edwin McDowell writes about the publishing industry for The Times

Published: November 26, 1989

After two loud blasts on the whistle the wood-burning steam locomotive pulls slowly out of the railroad yard, crowded with passengers clad mostly in bathing suits and shorts. But instead of heading for some fancy beach resort, the train is bound for a large pile of rocks in the middle of the Amazon jungle.

We are in Porto Velho, the river port capital of Rondonia, the Wyoming-sized Brazilian state that abuts Bolivia in the farthest reaches of the Amazon Basin. And our train is the legendary Madeira-Mamore Railway, the so-called Railway of the Devil, a monument to man's vision and myopia.

Conceived in the 19th century as part of a bold dream to link this fever-ridden region of South America to world markets via the Amazon River and the Atlantic Ocean, more than 2,000 miles away, the railroad was painstakingly hacked through the jungle at a record cost for that time of about $145,000 for each of its 228 miles. Its purpose was to provide a land route between Porto Velho and the Bolivian border, a stretch in which a series of falls and rapids rendered navigation impossible and made it almost impossible to get Bolivian rubber to markets in the United States and Europe.

Our train is filled with festive adults and fidgety children, who overflow all seven passenger cars. The train runs only one day a week, making as many as a half-dozen trips each Sunday, and then only until the rainy season brings downpours and surprisingly chilly winds. But now is the dry season, and we are headed for Santo Antonio, a settlement five miles away, the site of the first set of rapids and the end of the tourist line.

Eddie, my 11-year-old son, and I manage to find seats near the window on the 10:30 A.M. train, but the aisles are so crowded we cannot see out the other side.

And as we depart the train depot, which is situated on the banks of the Madeira River, the longest tributary of the Amazon, we move at a pace that not even the jungle's resident sloths would find taxing.

Successive 19th-century British, Brazilian and American construction companies made only the barest dent in the dense jungle wall.

After the money ran out and many workers died of malaria, yellow fever, beriberi and dysentery, the project lay fallow for a quarter-century. But Brazilian rubber gatherers wrested the adjoining territory of Acre from Bolivia in 1903, and the Brazilian Government agreed to pay its smaller neighbor two million pounds as well as build the illusive railway, to which both countries would have access.

In 1907 Percival Farquhar, a Yale graduate who had already electrified Havana's horse-drawn tramways and helped electrify Rio's street lights and houses, bought the railway concession. Assembling an international labor force that totaled about 23,000, he completed the railroad in five years - but at a cost in lives estimated at as high as 6,000.

The death rate would have been even higher, except that Farquhar built a 300-bed hospital and staffed it with American doctors and nurses. Doctors were also posted at outlying construction camps, and Dr. Oswaldo Cruz, the Walter Reed of Brazil, visited the project and supervised the fight against malaria and yellow fever. ''Oh, it was terrible,'' Silas Shockness, the tall, rugged head of the railroad's maintenance department, said of the death rate. ''People were dying like flies.''

Silas, as he's known to everyone (the name is pronounced SEE-less), has worked 42 years on the railroad. So did his father, who arrived in Porto Velho from his native Grenada in 1914, two years after the wife of an American contractor dedicated the railroad by driving a golden spike at its southern terminus at Guajara-Mirim, the town across the Mamore River from Bolivia. But even as the spike was being hammered into place, tons of rubber from seedlings that had been taken - some say spirited - from the Amazon 36 years earlier were making their way to world markets from plantations in Ceylon and Singapore, and at much lower prices than Amazon rubber.

Brazil's share of the world rubber market plummeted from more than 85 percent in 1910 to less than one-third by 1915. That falling demand exacted a heavy toll on the Madeira-Mamore Railroad, which soon reduced its schedule from three round trips a week to one. The money-losing line was shut down in 1972, but in 1980 the State of Rondonia reopened what was left of it as a tourist attraction, rehiring Silas and two of his brothers.

Despite daily jet service to and from several Brazilian cities, Porto Velho, a raw frontier town with a population of more than 300,000, is still too far out of the way for most visitors to South America. That may explain why this day Eddie and I appear to be the only foreigners aboard the train, as well as among the few passengers not preparing to make a day of it at the beach. As the train moves slowly out of the yard children dash from frail houses and shacks on either side of the tracks to wave at passengers.

Santo Antonio, our destination, was the headquarters for the various 19th-century construction crews, but it was also a malarial breeding ground. So Farquhar built his headquarters at Porto Velho, an uninhabited bluff five miles down the Madeira River. Soon transformed into a company town, Porto Velho had a baseball diamond, an ice plant, a movie theater and a bakery - plus a weekly newspaper, The Porto Velho Times (later The Courier), which billed itself as ''the best paper printed in the English language in North Brazil.''

Just beyond the wooden houses our train enters the jungle, and we are immediately enveloped by trees and scrub brush. From time to time we glimpse the slow-moving Madeira River, whose course the original train track more or less paralleled all the way to Bolivia. As the train creeps along, the mostly youthful crowd, including young parents with infants, is in high spirits, laughing and singing.

I remember having read that some of the workers were killed by jaguars and snakes, but most died of tropical diseases. In his travel classic, ''The Sea and the Jungle,'' H. L. Tomlinson - the British journalist who sailed on a British freighter for Porto Velho in 1909 -quoted an English employee of the railroad as saying: ''Most of the men on this job have not been here three months. They come and shovel a little dirt, and die. Or they get frightened, and go.''

Some who went did not go far. Six German laborers who deserted the railroad in 1908 were beheaded by Indians and their heads impaled on poles planted along the river bank.

The jungle still contains hidden dangers, yet the greatest danger in Rondonia these days is not from the jungle but to the jungle. This is because of the environmental destruction inflicted by settlers who have flocked to Rondonia in recent years over BR-364, the highway connecting Porto Velho to central Brazil and the industrialized south. Indiscriminately felling trees and burning the land, they have already destroyed almost 20 percent of the jungle in Rondonia. And, as elsewhere in the Amazon Basin, prospectors using mercury to separate gold from worthless ore have poisoned many of the rivers and streams in the world's largest freshwater system.

After about an hour our train lumbers into Santo Antonio and turns lazily around on a siding.

Passengers clamber down, and Eddie and I head for one of the half-dozen shacks that sell soda and guarana, the locally popular drink made from the seeds of a native Amazonian plant. Beneath the shade of a wooden roof we watch the picnickers flock toward the several large piles of graffiti-marked rocks high and dry on sandbars.

In the rainy season, from about January to June, the river rises as much as 40 feet in these parts, hissing, boiling and crashing against the tips of the submerged rocks as it roars past the rapids at Santo Antonio. But now the river is so placid it looks possible to wade the couple of hundred yards to the bank on the other side. And the rocks are a site for sun worshipers, the sandbars a playground for weekend athletes. Soon we walk to the nearest rock pile and climb five or six feet to the top. From our vantage point, little imagination is required to envision the area as Tomlinson saw it decades ago, when there was only wilderness for 1,000 miles in each direction.

Afterward we walk back up the hill and visit the whitewashed church built by Americans in 1913. A narrow, one-room structure, it consists of a simple raised altar flanked by 10 wooden benches with backrests and another 20 backless benches. A half-dozen of the faithful are praying silently, and I offer a prayer for the preservation of what is left of the jungle.

We spend another hour or so exploring and watching the sunbathers, almost none of whom venture into the water. When the train returns, disgorging its overflow load of sun worshipers, only a handful of us board for the return trip.

Back in Porto Velho, Silas and his brother Paul (who with brother Dennis also works on the railroad) take us on a tour of the railroad museum adjoining his workshop.

Here are displayed Waterbury clocks from England, aged maps, photographs of the railway under construction, and telegraph keys from the days when Porto Velho was connected to the outside world via the wireless station at Itacoatciara, a village at the confluence of the Mamore and Amazon Rivers, more than 900 miles away.

The brothers proudly show us a photograph of their father, a large, dignified-looking man with a steady gaze.

And they show us a steam engine made in 1878 by the Baldwin Locomotive Company of Philadelphia that is named for Col. George Early Church, a Massachusetts-born civil engineer who failed in his attempt to build the Madeira-Mamore Railway.

In his Spartan office Silas asks the American visitors to sign his guest book, and as they do so he says, ''I'd like to visit New York some day, but I wouldn't want to stay there.'' Looking up I see the railroad station out one door of the maintenance building and the Madeira River out another, and I know better than to ask why. ALL ABOARD THE JUNGLE RAILROAD Getting There

Cruzeiro and Vasp, domestic Brazilian airlines, offer several daily flights to Porto Velho from Rio de Janeiro and Sao Paulo, but make two or more stops and take five or six hours. The one-way fare from Rio is $291, from Sao Paulo $255. Brazilian carriers, however, offer an air pass for $330, good for unlimited 21-day travel. Passengers cannot fly to the same city more than once, and the pass must be bought in advance in the United States. Accommodations

All three of the following hotels in Porto Velho are air-conditioned and have swimming pools:

Hotel Vila Rica, 1616 Avenida Carlos Gomes (telephone 221-2286), is the newest and the best. Rates for a double room are $65.

Seltom Hotel, next door to the Vila Rica and using the same phone number, charges $35 for a double room.

Stick to the dining rooms of the three best hotels, where the food is satisfactory and the restaurants air-conditioned. All serve a variety of fish freshly caught in the Madeira River, spaghetti, and, of course, rice, beans and steak. Dinner for two runs $10 to $15 for two, plus drinks. The Rondon Palace Hotel has a daily luncheon buffet for $3.50. Here as everywhere outside of the large tourist hotels in the major cities, it is wise to drink only bottled water and avoid salads and fruit that you do not peel yourself.